Methods for rapid screening and isolation of bacteria producing acidic lipase: feasibility studies and novel activity assay protocols

Acidic lipase finds its commercial values in medical applications and bioremediation of food wastes. In this work, approaches for rapid screening of lipase-producing bacteria were developed and the feasibility assessment of the screening methods was performed. From food waste samples, the proposed screening procedures allowed isolation of sixteen pure bacterial strains expressing higher lipase activity at acidic pH (pH 6.0) than at alkaline pH (pH 9.0). To enhance the accuracy of lipase activity determination under acidic conditions, a novel assay procedure was also developed by deactivating lipase activity by microwave treatment prior to back titration. This additional step could minimize interferences arising from residual lipase activity during conventional direct back-titration methods in measuring lipase activity at acidic pH. Using the four strategies proposed in this work, the best acidic-lipase-producing isolate was obtained by strategy C (SSC) and was identified as Aeromonas sp. C14, displaying an optimal lipase activity of 0.7 U/ml at an acidic pH of 6.0.     

Microwave irradiation increases recovery of neuropeptides from brain tissues

The effect of focused high energy microwave treatment (MW) on brain concentrations and molecular forms of substance P, neurokinin A, neuropeptide Y, neurotensin, galanin and calcitonin gene-related peptide was investigated. Groups of rats were treated as follows: 1) MW, storage for 60 min at 22°C, 2) Decapitation, storage for 60 min at 22°C, 3) Decapitation, storage for 60 min at 22°C, MW treatment, 4) MW, decapitation, storage for 2 min at 22°C and 5) Decapitation, storage for 2 min at 22°C. Peptide concentrations were in all instances highest in the MW sacrificed groups. MW increased the concentration of intact peptides by rapid inhibition of peptidase activity and increase in peptide solubility/extractability.     

Interrelationships between water and cell metabolism in Artemia cysts X. Microwave dielectric studies

Artemia cysts are composed of an inner mass of about 4000 cells surrounded by an acellular shell. This system can undergo cycles of hydration-dehydration without viability loss, and is a useful model for the study of intracellular water. We have measured the relative permittivity (ε′) of these cysts as a function of water content over the frequency range 0.8–70 GHz. Detailed analysis of the data for cysts containing close to 1 g H₂O/g dry weight indicates that a significant fraction of the total water in this system exhibits dielectric behavior different from that of pure water: the distribution parameter (α) for the dispersion analyzed by the Cole-Cole equation deviates from zero, and the permittivity of cyst water appears to be significantly lower than that of pure liquid.     

Estimation of phenological stages and physiological states of grasslands from remote sensing data

Two radiometers measuring reflectance factors have been used at a height of 1.50 m above some grasslands in C. France. The results show that both spectral data are sensitive to the photosynthetic activity of the grassland. Measurements made in April, May, June and July show that grasslands have quite different spectral behaviour according to soil conditions or to grazing level. Grasslands on dry or wet soils may be separated from those of normal soils for which overgrazing and trampling affecting the growth of species, are shown by the different spectral values. Such on the ground remote sensing measurements may then be proposed for evaluating the range of growth and development of different grasslands.Convention C.N.E.S./I.N.A.P-G. ref.: 80/CNES/24 I thank CNES and IGN for the facilities given to assume this experiment. Many thanks to Lynn Erselius, who revised the text. Mr. Lecordix, a student from the Ecole Nationale des Sciences Géographiques and Mr. Besnard, a student from the Orsay University (Plant Biology) helped in the collection and handling of spectral resp, floristical data.     

三氯乙酸(TCA)提取法与微波提取法检测活性污泥中三磷酸腺苷(ATP)

【目的】针对活性污泥法中的重要参数ATP进行研究分析,通过在不同条件下检测污泥的活性,得出以ATP为指标的污泥活性状态,为准确判定活性污泥的活性提供依据。【方法】分别运用三氯乙酸(TCA)提取法及微波提取法检测活性污泥中的ATP,并对检测ATP的影响因素(TCA浓度、冰浴时间、p H、微波频率及时间等)进行探讨与优化。【结果】运用TCA提取法检测ATP时,在1.0%-7.0%的TCA体积百分数内,活性污泥中TCA最佳体积百分数为2.5%;在2-60 min的冰浴时间内,最佳冰浴时间为10 min;三羟甲基丙烷-乙二胺四乙酸(Tris-EDTA)缓冲液的最佳p H 7.5;运用微波提取法检测ATP适宜的微波辐射条件为:功率800 W,辐射时间15 s。【结论】TCA提取法和微波提取法均可以检测活性污泥中的ATP,但与微波提取法相比,TCA提取法更能保证从细胞内释放出来的ATP的完整性,因此TCA提取法更适合用于检测活性污泥中的ATP。     

免疫组织化学反应抗原恢复新法在临床病理诊断中的应用

应用蒸馏水在ｐＨ６２, 加热煮沸后能够较好的恢复组织中被封闭的抗原。经２８０４ 张组织切片在进行免疫组织化学反应之前, 用现配ｐＨ６２ 的蒸馏水加热煮沸后微火保温１０ 分钟, 然后再按常规免疫组化染色。经此法恢复抗原处理后, 并显示强度和阳性率与微波辅助盐溶液方法相比结果基本相似, 两者与未抗原恢复处理相比有显著性差异（Ｐ＜ ００１）。经彩色图像分析结果同样有显著性差异（Ｐ＜ ００５）。本法恢复抗原与微波技术相比, 同样能使组织内抗原得以充分的暴露, 提高抗原的检出率, 证明了蒸馏水在ｐＨ６２ 时,可作为一种新的暴露抗原的方法, 且操作简单, 抗原恢复均匀, 很适合各种实验室的应用     

Monitoring of microwave emission of HRP system during the enzyme functioning

Monitoring of microwave emission from aqueous solution of horseradish peroxidase (HRP) in the process of the enzyme functioning was carried out. For the monitoring, a system containing HRP, luminol and Н₂О₂ was employed. Microwave emission measurements were carried out in the 3.4-4.2 GHz frequency range using the active and passive modes (active-mode and passive-mode measurements). In the active mode, excitation of the solution in the pulsed electromagnetic field was accomplished. In the passive mode, no excitation was induced. It appears that the passive-mode measurements taken in the course of the peroxidase reaction in the enzyme system have shown a 0.5 °С increase of the microwave signal. Upon the active-mode measurements, taken in the same reaction conditions, the forced excitation of the solution has also led to the increase (by 2 °С) of the level of the microwave signal – i.e. to its 4-fold enhancement compared to the signal obtained in passive-mode measurements.     

二陈汤加减联合微波消融术对晚期非小细胞肺癌患者Th17/Treg失衡和血管生成因子的影响

摘要 目的：探讨二陈汤加减联合微波消融术（MWA）对晚期非小细胞肺癌（NSCLC）患者辅助性T细胞17（Th17）/调节性T细胞（Treg）失衡和血管生成因子的影响。方法：选择2020年9月~2022年9月期间我院收治的120例不可或不愿手术切除或体部立体定向放疗的ⅢB-Ⅳ期并同意MWA治疗的NSCLC患者。采用随机对照的方法将所有患者分为观察组（二陈汤加减联合MWA治疗,60例）及对照组（MWA治疗,60例）。对比两组中医主要证候总评分、EORTC生命质量测定量表（EORTC QLQ-C30）评分、Th17/Treg失衡、血清肿瘤标志物、血管生成因子和不良反应发生率。结果：治疗后,观察组中医主要证候总评分、EORTC QLQ- C30评分低于对照组（P<0.05）。治疗后,观察组Th17细胞比例、Treg细胞比例低于对照组,Th17/Treg比值高于对照组（P<0.05）。治疗后,观察组癌胚抗原（CEA）、鳞状细胞癌相关抗原（SCC-Ag）和角化素蛋白片段19（Cyfra21-1）低于对照组（P<0.05）。治疗后,观察组血管内皮生长因子（VEGF）和碱性成纤维细胞生长因子（bFGF）低于对照组（P<0.05）。两组不良反应发生率组间对比未见差异（P>0.05）。结论：二陈汤加减联合MWA对晚期NSCLC患者,可有效降低血清肿瘤标志物水平,促进临床症状改善,调节Th17/Treg比例失衡和血管生成因子。     

微波提取香水莲花总黄酮的工艺研究

该文研究了微波法提取香水莲花总黄酮的工艺。采用比色法测定黄酮的含量。利用单因素实验和正交实验考察了乙醇浓度、微波功率、微波时间、料液比对黄酮得率的影响,确定了最佳工艺为:用70%的乙醇溶液,微波功率250W,提取时间40 min,液料比25∶1,提取的总黄酮得率最高。     

Study of microwave effects on the lipase-catalyzed hydrolysis

The effect of microwave heating on lipase-catalyzed reaction remains controversial. It is not clear whether the reaction rate enhancements are purely due to thermal/heating effects or to non-thermal effects. Therefore, quantitative mass spectrometry was used to conduct accurate kinetic analysis of lipase-catalyzed hydrolysis of triolein by microwave and conventional heating. Commercial lipases from Candida rugosa (CRL), Porcine Pancreas (PPL), and Burkholderia cepacia (BCL) were used. Hydrolysis reactions were performed at various temperatures and pH levels, along with various amounts of buffer and enzymes. Hydrolysis product yields at each time point using an internal-standard method showed no significant difference between microwave and conventional heating conditions when the reaction was carried out at the same temperature. CRL showed optimum catalytic activity at 37 °C, while PPL and BCL had better activities at 50 °C. The phosphate buffer was found to give a better hydrolysis yield than the Tris–HCl buffer. Overall results prove that a non-thermal effect does not exist in microwave-assisted lipase hydrolysis of triolein. Therefore, conventional heating at high temperatures (e.g., 50 °C) can be also used to accelerate hydrolysis reactions.